From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Study of W.W. Flywheel vibration patterns with and without a tail bearing at various RPMs.
| Identifier | ExFiles\Box 137\4\ scan0171 | |
| Date | 13th January 1931 guessed | |
| IV-G-6 {W.W. FLYWHEEL} WITHOUT TAIL BEARING 2500 3060 3600 WITH TAIL BEARING (BALL RACE) -> 2900 3100 | ||